Given A,B,C can complete a work in 15,20 and 30 respectively. The total work is given by the LCM of 15, 20, 30 i.e, 60. A's 1 day work = 60/15 = 4 units B's 1 day work = 60/20 = 3 units C's 1 day work = 60/30 = 2 units (A + B + C) worked for 2 days = (4 + 3 + 2) 2 = 18 units  Let B + C worked for x days = (3 + 2) x = 5x units C worked for 2 days = 2 x 2 = 4 units Then, 18 + 5x + 4 = 60 22 + 5x = 60 5x = 38 x = 7.6   Therefore, total number of days taken to complete the work = 2 + 7.6 + 2 = 11.6 = 11 3/5 days.

Answer: B) 17.5 days Explanation: Let the number of days be 'p'  As the work is same, we know that M1 x D1 x H1 = M2 x D2 x H2 Where M = Men, D = Days, H = Hours per day  Here M1 = 9, D1 = 15, H1 = 7  M2 = 6, D2 = p, H2 = 9  => 9 x 15 x 7 = 6 x p x 9  => p = 35/2 = 17.5 days.

Answer: C) 78% Explanation: Let Akhil's weight = p kg => Shreyon's weight = 2p kg Nani's weight = 0.9 x 2p = 1.8p kg => Arun's weight = 1.4p kg Required percentage = 1.4p1.8p x 100 = 77.8% ~= 78%

Answer: B) Respirometer Explanation: A respirometer is a device used to measure the rate of respiration of a living organism by measuring its rate of exchange of oxygen and/or carbon dioxide.

Answer: A) 145 Explanation: 4       30       ?     1440       7195      71940   Here the given series follows a pattern of   4   4 x 10 - 10 = 30   30 x 5 - 5  = 145   145 x 10 - 10 = 1440   1440 x 5 - 5 = 7195   7195 x 10 - 10 = 71940   Hence, the missing number is 145

Answer: D) Rs. 3136 Explanation: Let total amount = Rs. P Total expenditure = (23 + 33 + 19 + 16)% of P = 91%ofP Remaining money = (100 - 91)% of P = 9% of P But given in the question that, 9% of P = 504 9p/100 = 504 => P = 50400/9 => P = Rs. 5600   Required money spent on Food & Insurance = 23 + 33 % = 56% of 5600 = 56 x 5600/100 = 56 x 56 = Rs. 3136

Answer: C) 6 Explanation: ?2 = 2×78-21+8+49-148= 57 - 21=36=> ? = ±6

Answer: A) 200 mts Explanation: Length of train A = 48 x 9 x 5/18 = 120 mts Length of train B = 48 x 24 x 5/18 - 120 => 320 - 120 = 200 mts.